Radiocarbon dating calibration curve Afghanxxx
Intcal extended radiocarbon dates beyond the limit of dendrochronology by basing it on “matched uranium series and radiocarbon dates on fossil corals, coupled with radiocarbon-dated organic material from laminated marine sediments in the Cariaco Basin, Venzuela” (Mike Walker, Quartenary Dating Methods, 2005). They apparently increased the effectiveness of radiocarbon dating by basing their calibration charts on radiocarbon-dated coral and sediment layers!That is circular reasoning—defending the method by using the very same method!Since the early 1980s, an international working group called INTCAL has been working on the project.The principle of radiocarbon dating is that plants and animals absorb trace amounts of radioactive carbon-14 from carbon dioxide in the atmosphere while they are alive but stop doing so when they die.So even though it is less reliable and has some serious problems, scientists ignore that and still use it.
Once the “clock” starts, there is no gain or loss in radiocarbon elements used in dating. In coral, the carbon-14 decay rate is not stable; it picks up radioactive isotopes over time.
The carbon-14 decays from archaeological and geological samples so the amount left in the sample gives an indication of how old the sample is.
As the amount of carbon -14 in the atmosphere is not constant, but varies with the strength of Earth's magnetic field, solar activity and ocean radiocarbon ages must be corrected with a calibration curve. These are often very tricky questions to answer and frequently arise in judicial contexts.
It not only extends radiocarbon calibration but also considerably improves earlier parts of the curve.
Dr Ron Reimer of the Queen's School of Geography, Archaeology and Palaeoecology said: "The new radiocarbon calibration curve will be used worldwide by archaeologists and earth scientists to convert radiocarbon ages into a meaningful time scale comparable to historical dates or other estimates of calendar age.
Ron Reimer and Professor Emeritus Mike Baillie from Queen's School of Geography, Archaeology and Palaeoecology also contributed to the work. "Archaeological 'time machine' greatly improves accuracy of early radiocarbon dating." Science Daily.